Abstract: Objective To explore and analysis the values of high-frequency ultrasound in the differential diagnosis of partial and full-thickness small tear rotator cuff injuries. Methods From October 2020 to January 2022, 70 cases of patients with partial and full-thickness small tear rotator cuff injuries who were diagnosed and treated in The Sixth Division Hospital of Xinjiang Production and Construction Corps were selected as the research subjects. All patients were given arthroscopy and high-frequency ultrasonography, the images characteristics were recorded and determined the diagnostic values. Results In the 70 patients, there were 50 cases of partial small tear rotator cuff injury (partial group) and 20 cases of full-thickness small tear rotator cuff injury (full-thickness group) were diagnosed by arthroscopy. There was no significant difference compared between the two groups in terms of injury site, time from injury to ultrasound, body mass index, gender, and age (P>0.05). In the full-thickness group, the proportions of ultrasonographic features such as hydrocele, rotator cuff calcification, tendon degeneration, and tendon thickening were significantly higher than the partial group(P<0.05). The myofascial thickness, infraspinatus tendon thickness and supraspinatus tendon thickness in the full-thickness group were significantly higher than those in the full-thickness group, the difference is statistically significant (P<0.05). In the 70 patients, there were 19 cases were diagnosed as full-thickness small tear rotator cuff injury by high frequency ultrasound, and 51 cases were partial small tear type rotator cuff injury. The sensitivity and specificity of high-frequency ultrasonography in the differential diagnosis of partial and full-thickness small tear rotator cuff injuries were 90.0% (18/20) and 98.0% (49/50), respectively, Kappa value is 0.893. The ROC curve showed that the area under the curve of high-frequency ultrasound for differential diagnosis of partial and full-thickness small tear rotator cuff injuries was 0.914. Conclusion Full-thickness small tear rotator cuff injuries are mainly manifested by hydrocele, rotator cuff calcification, tendon degeneration, and tendon thickening on ultrasound, especially the thickness of myofascial, infraspinatus and supraspinatus tendons. In addition, high-frequency ultrasonography has high sensitivity and specificity in the differential diagnosis of partial and full-thickness small tear rotator cuff injuries, with a high degree of concordance with the diagnosis of arthroscopy.

Key words: full-thickness small tear rotator cuff injury, high-frequency ultrasound, hydrocele, rotator cuff calcification, tendon degeneration, tendon thickening